Tools: hv: Fix a bug in the key delete code

Fix a bug in the key delete code - the num_records range
from 0 to num_records-1.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Reported-by: David Binderman <dcb314@hotmail.com>
Cc: <stable@vger.kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>